Method for reutilization of residue from crude terephthalic acid product

A technology for terephthalic acid and crude products is applied in the field of recycling terephthalic acid crude product residues, and can solve the problems of limited recycling and utilization of CTA residues, high operating costs, complicated extraction processes and the like

Inactive Publication Date: 2004-08-18
EAST CHINA UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

And because the CTA residue is a mixture of various benzenecarboxylic acids, organic acidic substances will inevitably cause adverse environmental impacts around the stacking site
Although there are paints produced by esterification of CTA residues with alcohols, there are certain requirements for the composition of CTA residues, and the composition of CTA residues cannot be controlled artificially, so it limits the recycling of CTA residues.
There are also CTA residues separated by reaction extraction to recover isophthalic acid and mixed unit benzenecarboxylic acid, but due to the complexity of the reaction extraction process, high energy consumption, high operating costs, and the separation of mixed benzenecarboxylic acid, it has not been accepted by the market. The recalled product is unmarketable due to acceptance
Therefore, the CTA residue has not been well comprehensively utilized due to technical and economical reasons so far.

Method used

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  • Method for reutilization of residue from crude terephthalic acid product
  • Method for reutilization of residue from crude terephthalic acid product

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Put the measured CTA residue, formic acid, ethylene glycol and sulfuric acid into an esterification tank with a water separation system, and heat it to boiling under normal pressure. The water in the CTA residue and the water generated by esterification are continuously discharged from the water separator separated out. After most of the water is azeotropically distilled off, continue heating until no water is distilled off. Stay at this temperature for a period of time and measure its acid value. When the acid value is close to the acid value of the acid catalyst added, it is regarded as the end point of esterification, and the temperature is lowered to about 80°C, and then enters the neutralization stage.

[0029]Add an aqueous sodium carbonate solution whose consumption is 1.5 times the acid value measured to the above mixed crude ester, stir for half an hour, then settle still, and separate the water layer to obtain the neutralized crude ester. Heat the crude este...

Embodiment 2-7

[0031] The procedure of Example 1 was repeated except that different starting materials and reaction conditions were used. The specific raw materials, reaction conditions and results of each embodiment are listed in Table 1.

[0032] Example 1

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

fatty acid

formic acid

Acetic acid

Acetic acid

Acetic acid

C 3-7 Monobasic acid

C 3-7 Monobasic acid

C 8-10 Monobasic acid

diol

Ethylene glycol

Diethylene glycol

Diethylene glycol

Dipropylene glycol

Diethylene glycol

Butanediol

Decanediol

CTA Residue: Fatty Acid:

The molar ratio of glycol

1.0∶0.8∶1.0

1.0∶9.0∶5.0

1.0∶0.4∶0.8

1.0∶0.2∶0.9

1.0∶4.5∶3.0

1.0∶0.7∶0.9

5

1.0∶0.3∶0.8

5

catalyst

sulfuric acid

Toluenesulfonic acid

sulfuric acid

Molecular sieve

Potassiu...

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Abstract

The present invention is the method of recovering and using coarse terepthalic acid (CTA) residue and the method includes adding fatty acid, dihydric alcohol and catalyst in catalytic amount to catalytically esterify to produce mixed coarse ester, with the molar ratio among residue, fatty acid and dihydric alcohol being 1.0 to 0.2-9.0 to 0.8-5.0. The present invention has the advantages of one-step esterification of CTA residue to obtain mixed ester, short technological process, saving in energy source and low cost, and the outstanding advantage is the comprehensive utilization of CTA residue as industrial resource.

Description

technical field [0001] The present invention relates to the recycling method of the by-product industrial solid waste in the process of oxidizing p-xylene to terephthalic acid, that is, the crude product residue of terephthalic acid (hereinafter referred to as CTA residue), especially relates to the method of combining CTA residue with fatty acid and glycol The method of preparing plasticizer through esterification reaction. Background technique [0002] CTA residue is the benzenecarboxylic acid residue produced in the process of oxidizing p-xylene to terephthalic acid, which is based on phthalic acid (there are three isomers: ), benzoic acid, methylbenzoic acid, p-carboxybenzaldehyde and other benzene carboxylic acid mixtures as the main components. [0003] The composition of CTA residue is complex, and its composition content varies greatly with the fluctuation of oxidation conditions. At present, CTA residue is disposed of as industrial solid waste by incineration, lan...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/08C08K5/10
Inventor 何美琴高健翼王评童天中应再正杨晓冬
Owner EAST CHINA UNIV OF SCI & TECH
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